Conventional potentiometric sensors are based on the principle that, between at least two electrodes, an electrical voltage can be measured which changes with the change in the concentration of a chemical specimen. The voltage to be measured is produced by an electrical potential difference, which results from a difference in the chemical equilibrium potential of the individual electrodes with respect to their environment.
Such conventional sensors are used, for example, as oxygen sensors or as an electrochemical sulfuric acid cell for measuring carbon monoxide.
In addition, so-called gas electrodes or standard hydrogen electrodes are used for measuring acidic components in liquids or gases, i.e., for determining a hydrogen-ion concentration or a pH value, in mostly aqueous media. Furthermore, so-called diaphragm electrodes, such as a glass pH electrode or other solids having an ion-sensitive effect, are used for measuring pH values in liquid media.
In this context, however, the conventional potentiometric sensors used to measure pH values have the disadvantages of being costly to manufacture and having a low mechanical load-bearing capacity.